库水升降作用下三峡库区三门洞滑坡变形响应特征

三峡库区三门洞滑坡自设立专业监测设施以来,一直发生持续蠕滑变形。通过野外调查、GPS监测数据分析,并运用Geo-studio有限元软件对滑坡进行渗流场模拟,分析了库水位不同升降速率下滑坡的稳定性。研究结果表明:①库水位上升时,滑坡的稳定性呈上凸型,表现为先上升后下降;当滑坡以1.6 m/d的速率上升时,滑坡稳定性最大。②库水位下降时,滑坡的稳定性呈下凹型,表现为先下降后上升;不同降速下的稳定性极值不同,但最终的稳定性基本保持一致。③三门洞滑坡作为典型的堆积体滑坡,库水位的升降是导致滑坡发生变形的主要因素,目前一直处于蠕滑变形状态,但不会发生整体性破坏。

Deformation characteristics of Sanmendong landslide in Three Gorges Reservoir area under reservoir water fluctuation

Since the establishment of professional monitoring for Sanmendong landslide in Three Gorges Reservoir area, it was found that the landslide had experienced continuous creep deformation. Through field investigation and GPS monitoring data analysis, the seepage field of landslide was simulated by Geo-studio finite element software and the stability of landslide under different fluctuation rates of reservoir water was analyzed. The results showed that:① When the reservoir water level rose, the distribution of landslide stability was convex, it rose initially then fell and it reached the highest stability at the rising rate of 1.6 m/d.② When the water level of the reservoir dropped, the distribution of landslide stability was concave, it dropped initially then rose. The peak values of stability were varied under different fluctuation rates, but it finally reached a same value.③ As a typical accumulation body landslide, the rise and fall of reservoir water level were the main factors that lead to deformation of the landslide. At present, Sanmendong landslide has been in the state of creep deformation, but it will not slip as a whole.